Empirical data suggests that most arylacetic acid type anti- inflammatory agents could fit a common receptor. This project involves the synthesis and evaluation of conformational analogs of indomethacin in order to investigate the suggestion that the benzoyl or aryl moiety must be "cis" but non-coplanar. It is proposed that a rigid skeleton in which the benzoyl moiety is fused into ring systems of varying geometry will give rise to an agent with optimum activity and fewer side effects. The ultimate objective is the design of agents of value in the treatment of inflammatory and arthritic diseases.